FREQUENT OCCURRENCE OF TRANSPOSABLE PHAGES IN NATURAL-POPULATIONS OF PSEUDOMONAS-AERUGINOSA

Abstract

Five phages (PH2, PH51, PH59, PH93 and PH132) which have some characteristics common with D3112, the transposable phage of P. aeruginosa, were isolated from clinical P. aeruginosa isolates. The phages were distributed into 4 different immunity groups. The basic criteria used for selection of transposable phages were: morphology of a phage particle, host range, similar inactivation with antiserum; similar sizes of phage genomes; and the presence of a variable non-phage nucleotide sequences covalently linked to phage genome DNA, which could be identified using restriction endonucleases or by heteroduplex analyses. The DNA of the new phages are resistant to treatment with BamHI endonuclease, like the DNA of phages D3112, B39 and B3 described earlier. The restriction maps of the phage genomes are constructed.